This invention relates to a conduit for molten glass, and more particularly to a conduit for conducting molten glass from a glass melting furnace for delivery to glassware forming equipment.
The invention is especially concerned with a conduit structure embodied in what is referred to as a "forehearth" for delivery of molten glass to a spout, where it is formed into gobs which are subsequently formed into the desired glassware articles, from what may be referred to as an "alcove" such as shown in the co-pending co-assigned U.S. Pat. No. 4,750,928. Reference may be had to U.S. Pat. Nos. 3,999,972, 4,494,974, and 4,553,579 for disclosures of such forehearths. While the invention is especially concerned with forehearths, it is to be understood that the principles of the present invention are also applicable to alcoves, and the term "conduit"as used herein is used in a broad sense encompassing conduits useful in alcoves as well as in forehearths.
Forehearths presently used in glass making lines are essentially elongate troughs of refractory material assembled in place from a number of individual blocks. A roof is provided for the trough, and this roof is assembled in place over the trough, also from a number of individual blocks. In the harsh, high temperature service conditions on the glass making line, the refractory material, particularly that forming the trough, erodes and must be replaced. This requires that the roof be completely disassembled and removed to gain access to the trough. The entire trough is then disassembled and the damaged blocks replaced. Finally the trough and roof are reassembled. This is difficult and time consuming work. The task is made more difficult because it must be carried out in the midst of the glass making line, and access is hampered by the supporting superstructure of the conduit as well as the surrounding equipment. Furthermore, since the work is being done on the line, it puts at least a portion of the glass making equipment out of service for a considerable time.